Idiopathic intracranial hypertension (IIH), also called pseudotumor cerebri, is a disorder of elevated intracranial pressure of unknown cause [Corbett, et al., 1982; Wall, et al., 1991]. Its incidence is 22.5 new cases each year per 100,000 overweight women of childbearing age, and is rising [Garrett, et al., 2004] in parallel with the obesity epidemic. It affects about 100,000 Americans. Most patients suffer debilitating headaches. Because of pressure on the optic nerve (papilledema), 86% have some degree of permanent visual loss and 10% develop severe visual loss [Wall, et al., 1991]. Interventions to prevent loss of sight, all with unproven efficacy, include diet, diuretics such as acetazolamide, repeated spinal taps, optic nerve sheath fenestration surgery, and cerebrospinal fluid (CSF) shunting procedures. The purported goal of these therapies is to lower intracranial pressure; however, it is unclear which treatments work and by what mechanism. None of these strategies has been verified by properly designed clinical trials. Thus, there is confusion, uncertainty, and weak scientific rationales to guide treatment decisions. This trial will study subjects who have mild visual loss from IIH to (1) establish convincing, evidence-based treatment strategies for IIH to restore and protect vision, (2) follow subjects up to 4 years to observe the long-term treatment outcomes and (3) determine the cause of IIH. To meet those aims, the trial will be divided into a 12-month intervention phase and a 3-year observational phase. Subjects are not required to complete the observational phase of the study, but will be asked to do so and consented for the observational phase of the study at the conclusion of the intervention phase (12 months).

Subjects will begin with four 250 mg tablets daily. Tablets will be divided among two doses, taken with meals. Beginning on day 7, subjects will increase the dose by 1 pill every week until 16 tablets daily is reached (4 grams acetazolamide or placebo) or side effects prohibit increasing the dosage further. Thus, subjects who are able to tolerate the study medication will reach the maximum dose by day 84.

Other Names:

naproxen

acetaminophen

aspirin

ibuprofen

codein

butalbital

Behavioral: Formal weight loss counselling program

Teleconference, web-based from central location, using site visits and subject self-assessment tools

Other Names:

naproxen

acetaminophen

aspirin

ibuprofen

codein

butalbital

Placebo Comparator: Sugar pill

Given in escalating "dose" (number of pill)

Drug: Placebo

Subjects will begin with four tablets daily. Tablets will be divided among two doses, taken with meals. Beginning on day 7, subjects will increase the dose by 1 pill every week until 16 tablets daily is reached (4 grams acetazolamide or placebo) or side effects prohibit increasing the dosage further. Thus, subjects who are able to tolerate the study medication will reach the maximum dose by day 84.

Other Names:

naproxen

acetaminophen

aspirin

ibuprofen

codein

butalbital

Behavioral: Formal weight loss counselling program

Teleconference, web-based from central location, using site visits and subject self-assessment tools

CSF pressure less than 200 mm water (patients may have repeat CSF pressure measurements if the first is normal or no opening pressure obtained)

Abnormal CSF contents: increased cells: > 5 cells, elevated protein:

> 45 mg%, low glucose: < 30 mg% (If the lumbar puncture produces a cell count compatible with a traumatic needle insertion, the patient does not need to be excluded if the CSF WBC after correction is 5 wbc/mm3 or less- see Operations Manual for calculation) 8. Intraocular pressure currently > 28 mm Hg or > 30 mm Hg at any time in the past 9. Refractive error > +/- 6.00 sphere or > +/- 3.00 cylinder in either eye with the following exceptions: Subjects with myopia of >-6.00 D sphere but less than or equal to - 8.00 D sphere are eligible if 1)there are no abnormalities on ophthalmoscopy or fundus photos related to myopia that are associated with visual loss (such as staphyloma, retinal thinning in the posterior pole or more than mild optic disc tilt), and 2) the subject wears a contact lens for all perimetry examinations with the appropriate correction. If either the Site Investigator or the PRC director (or his designate) decides there are optic fundus abnormalities of myopia that are associated with visual loss, then 9. Subjects with hyperopia of > +6.00 D but less than or equal to

8.00 D sphere are eligible if 1) there is an unambiguous characteristic halo of peripapillary edema as opposed to features of a small crowded disc or other hyperopic change related to visual loss determined by the site investigator or the PRC director (or his designate) and 2) the subject wears a contact le 10. Other disorders causing visual loss except for refractive error and amblyopia including cells in the vitreous or iritis 11. Optic disc drusen on exam or in previous history 12. Presence of diagnosed untreated obstructive sleep apnea 13. Inability to provide reliable and reproducible visual field examination (failure to maintain fixation using an eye monitoring device, more than 15% false positive errors) 14. Abnormal blood work-up indicating a medical or systemic condition associated with raised ICP 15. Study blood results showing severe anemia, leukopenia or thrombocytopenia, renal failure, or hepatic disease, based on the Site Investigator's judgment 16. Type I diabetes or the presence of diabetic retinopathy 17. Exposure to a drug, substance or disorder that has been associated with elevation of intracranial pressure within 2 months of diagnosis such as lithium, vitamin A, various cyclines (see table in Operations Manual for conditions and drugs) 18. Other condition requiring diuretics, oral, I.V. or injectable steroids or other pressure lowering agents including topiramate (nasal, inhaled, or topical steroids are allowed since the systemic effects are small) 19. Presence of a medical condition such as renal stones that would contraindicate use of the study drug (acetazolamide) 20. Pregnancy or unwillingness for subject of childbearing potential to use contraception during the first year of the study 21. Breastfeeding mothers are excluded from participation unless willing to discontinue breastfeeding by the baseline visit 22. Presence of a physical, mental, or social condition likely to affect follow-up (drug addiction, terminal illness, no telephone, homeless) 23. Anticipation of a move from the site area within six months and unwillingness to return for follow-up at an IIHTT study site 24. Allergy to pupil dilating drops or narrow angles precluding safe dilation

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Please refer to this study by its ClinicalTrials.gov identifier: NCT01003639